<?php

namespace app;

use GuzzleHttp\Client;

class Wechat
{
    private $appId;
    private $appSecret;

    public function __construct($appId, $appSecret)
    {
        $this->appId = $appId;
        $this->appSecret = $appSecret;
    }

    public function getSignPackage(): array
    {
        $jsapiTicket = $this->getJsApiTicket();
        // 注意 URL 一定要动态获取，不能 hardcode.
        $url = request()->param("url", request()->server("HTTP_REFERER"));
        $timestamp = time();
        $nonceStr = $this->createNonceStr();

        // 这里参数的顺序要按照 key 值 ASCII 码升序排序
        $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url";

        $signature = sha1($string);

        $signPackage = array(
            "appId" => $this->appId,
            "nonceStr" => $nonceStr,
            "timestamp" => $timestamp,
            "url" => $url,
            "signature" => $signature,
            "rawString" => $string
        );
        return $signPackage;
    }
    public function getSignPackageUni(): array
    {
        $jsapiTicket = $this->getJsApiTicket();
        // 注意 URL 一定要动态获取，不能 hardcode.
        $url = request()->param("url", request()->server("HTTP_REFERER"));
        $timestamp = (string)time();
        $nonceStr = $this->createNonceStr();

        // 这里参数的顺序要按照 key 值 ASCII 码升序排序
        $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url";

        $signature = sha1($string);

        $signPackage = array(
            "appId" => $this->appId,
            "nonceStr" => $nonceStr,
            "timestamp" => $timestamp,
            "url" => $url,
            "signature" => $signature,
            "rawString" => $string
        );
        return $signPackage;
    }

    private function createNonceStr($length = 16)
    {
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

    private function getJsApiTicket()
    {
        $ticket_cache = cache("wechatApiTicket");
        if ($ticket_cache) {
            $ticket = $ticket_cache['ticket'];
        } else {
            $flag = 1;
            while (true) {
                $accessToken = $this->getAccessToken();

                // 如果是企业号用以下 URL 获取 ticket
                // $url = "https://qyapi.weixin.qq.com/cgi-bin/get_jsapi_ticket?access_token=$accessToken";
                $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
                $res = json_decode($this->httpGet($url), true);
                if ($res['errcode'] == 0 && $res['errmsg'] == 'ok') {
                    $ticket = $res['ticket'];
                    cache("wechatApiTicket", $res, $res['expires_in'] - 300);
                    break;
                } else {
                    if ($flag > 2) {
                        cache('accessToken_client', null);
                        $flag = 0;
                    }
                    $flag++;
                }
            }
        }
        return $ticket;
    }

    private function getAccessToken()
    {
        // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
        // 如果是企业号用以下URL获取access_token
        // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
        $cacheName = 'accessToken_client';
        if (cache($cacheName)) {
            $access_token = cache($cacheName);
            $access_token = $access_token['access_token'];
        } else {
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
            $res = json_decode($this->httpGet($url), true);
            $access_token = $res['access_token'] ?? "";
            if (!empty($access_token)) {
                cache($cacheName, $res, $res['expires_in']);
            }
        }
//        echo $access_token;

        return $access_token;
    }

    private function httpGet($url): string
    {
        $client = new Client(['verify' => false, "base_uri" => $url]);
        $content = $client->get("");
        return $content->getBody()->getContents();
    }
}
